Disease and sprout control in individually film wrapped potatoes     

Kiran K. Shetty  Robert B. Dwelle 《American Journal of Potato Research》1990,67(10):705-718

Potatoes (Solanum tuberosum L. cv Russet Burbank) were individually wrapped in Cryovac D-955, a biaxially oriented shrink film, and stored at 24°C. The wrapped potatoes were either treated with a fungicide (thiobendazole), or the film itself was coated with an antimicrobial agent (silicon quaternary ammonium salt) to control diseases that may appear during storage and marketing. Under film wrapped conditions, disease control using a fungicide or antimicrobial agent was not completely successful; however, the marketable qualities of the potatoes were not affected. Disease spread under film wrapped conditions was minimized if the potatoes were disinfected in chlorine (0.5% sodium hypochlorite) and wrapped after they were dried. In another study dormant and post-dormant potatoes were individually film wrapped after they were treated with maleic hydrazide (MH) (pre-harvest treatment) or isopropyl N-(3-chlorophenyl) carbamate (CIPC) (postharvest treatment) for sprout control. Under film wrapped conditions, MH decreased sprouting in the dormant potatoes but not in the post-dormant potatoes. CIPC inhibited sprouting in the post-dormant film wrapped potatoes but was less effective in the dormant potatoes.  相似文献   

Potential existence of multiple Tylenchulus semipenetrans biotypes in South Africa     

R.V. Mathabatha  N.M. Mokgalong  Z.P. Dube 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(7):673-679

The existence of multiple Tylenchulus semipenetrans biotypes within a citrus-producing region complicates the selection of nematode-resistant rootstocks for managing the slow decline of citrus. The potential existence of multiple T. semipenetrans biotypes in South Africa was investigated under greenhouse conditions on differential host plants using nematode isolates from 18 citrus-producing districts with at least six diverse soil groups and three different climates. After three nematode generations, the regional effects had no influence on final nematode population densities, whereas the differential host plants significantly segregated the nematode reproductive potentials. On Olea europaea reproductive potentials (eggs and juveniles/g) were zero, whereas those on Citrus jambhiri and Poncirus trifoliata ranged from 79 to 482 and 86 to 433, respectively. All T. semipenetrans isolates, regardless of the soil group and climate type, behaved similarly to the Poncirus biotype, which therefore rules out the existence of multiple T. semipenetrans biotypes in South Africa.  相似文献   

Agronomic evaluation of controlled release of micro urea encapsulated in rosin maleic anhydride adduct     

Zahid Majeed  Kiran Khurshid  Zainab Ajab  Qingjie Guan  Basharat Ahmad  Irsa Mumtaza 《Journal of plant nutrition》2020,43(12):1794-1812

Abstract

Plant derived bio-based materials are environmental-friendly and provide a cheap and an attractive source for synthesis of controlled release urea fertilizers which have positive impact on plants’ health. In this work, application of rosin-maleic anhydride adduct encapsulated controlled release micro urea fertilizer (RA-mCRUF) was investigated for the optimization of its controlled urea release properties and evaluation of growth promoting effect on maize (Zea mays) plant under three different soil texture classes. Through response surface methodology, the independent response variables, were optimized for controlled release response of urea. Study found optimized coating repeats, 5.00 cycles; drying time, 11.71?h; and particle size, 41.82?µm; at urea release response of 331.62?mg L^?1 in distilled water. Optical microscopy images further demonstrated a more compact and homogeneous surface of RA-mCRUF without any coating defects. Besides, RA-mCRUF predicted a better growth performance of maize plant in clay loam soil. Moreover, RA-mCRUF treated maize plant showed 9.0–24.5?mg g^?1 increase in chlorophyll contents and 7.44–12.75?g rise in plant dry biomass. This work successfully produced a new type of RA-mCRUF which has applied role in soil nutrients conservation and addressing effectively food security through crops protection.  相似文献   

Spatial and temporal trends in soil N-mineralization rates under the agroforestry systems in Bhabhar belt of Kumaun Himalaya,India     

Karki  Himani  Bargali  Kiran  Bargali  S. S. 《Agroforestry Systems》2021,95(8):1603-1617

To access the process of nitrogen mineralization in soil, the buried-bag technique was used among traditional agroforestry systems in the Bhabhar belt of Kumaun Himalaya. The present study, determined the relationship between various parameters of N-mineralization with agroforestry systems, seasons and soil depths. Season and soil depth have significantly (p?<?0.001) affected the process of ammonification, nitrification and net N-mineralization. The soil ammonium-N pool was comparatively higher than the nitrate-N pool. Highest amount of ammonium and nitrate-N were recorded in the agri-horticulture (AH) system, and lowest in the agri-horti-silviculture (AHS) system. Among the systems, highest amount of inorganic-N (ammonium?+?nitrate) was recorded during rainy season while, lowest during winter season. The highest ammonification rate (6.47?±?1.47 mg kg^?1 month^?1) was observed in agri-silviculture system and lowest (5.67?±?1.68 mg kg^?1 month^?1) in AHS system, while nitrification value was maximum (2.53?±?0.40 mg kg^?1 month^?1) in AH system and minimum (2.23?±?0.37 mg kg^?1 month^?1) in AHS system. The values of net N-mineralization were ranged from 4.03?±?0.53 to 13.29?±?0.44 mg kg^?1 month^?1. The values of inorganic-N and net N-mineralization were significantly more (P?<?0.01) in the surface soil layer (0–20 cm) than the subsurface layers (20–40 cm and 40–60 cm). Nitrogen mineralization was negatively correlated with the soil pH and positively correlated with soil organic carbon and total soil nitrogen. Higher rate of N-mineralization in AHS system indicated rapid turnover of nitrogen due to soil management practices and suggested that the changes in agroforestry based land-use systems alter the process of net N-mineralization, nitrification and ammonification.

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An <Emphasis Type="Italic">in-vivo</Emphasis> study of the efficacy and safety of ethno-veterinary remedies used to control cattle ticks by rural farmers in the Eastern Cape Province of South Africa     

B. Moyo  P. J. Masika  S. Dube  V. Maphosa 《Tropical animal health and production》2009,41(7):1569-1576

Ticks feed on blood, are vectors of tick-borne diseases and cause considerable skin damage to livestock. They are commonly controlled using commercial acaricides, which are expensive to the rural farmers, causing them to resort to alternative tick control methods. The objective of this study was to assess the acaricidal properties and safety of some materials (Ptaeroxylon obliquum, Aloe ferox, Lantana camara, Tagetes minuta, Used engine oil and Jeyes fluid, used by rural farmers to control cattle ticks in the Eastern Cape Province, South Africa. A total of 52 cattle were divided into 13 experimental groups with 4 cattle in each. Jeyes fluid at 76.8% concentration and Used engine oil had an efficacy that was almost similar to that of the positive control Ektoban® (Cymiazol 17.5 and cypermethrin 2.5%). Extracts of L. camara at 40% concentration had an efficacy of 57% while A. ferox, P. obliquum and T. minuta were not effective. The test materials had no irritation effect on rats. The study revealed that the materials rural farmers use as acaricides vary in their efficacy in controlling ticks.  相似文献   

Investigating maternal effects on production traits in Duroc pigs using animal and sire models     

B. Dube  S.D. Mulugeta  K. Dzama 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2014,131(4):279-293

Variance components for production traits were estimated using different models to evaluate maternal effects. Data analysed were records from the South African pig performance testing scheme on 22 224 pigs from 18 herds, tested between 1990 and 2008. The traits analysed were backfat thickness (BFAT), test period weight gain (TPG), lifetime weight gain (LTG), test period feed conversion ratio (FCR) and age at slaughter (AGES). Data analyses were performed by REML procedures in ASREML, where random effects were successively fitted into animal and sire models to produce different models. The first animal model had one random effect, the direct genetic effects, while the additional random effects were maternal genetic and maternal permanent environmental effects. In the sire model, the random effects fitted were sire and maternal grand sire effects. The best model considered the covariance between direct and maternal genetic effects or between sire and maternal grand sire effects. Fitting maternal genetic effects into the animal model reduced total additive variance, while the total additive variance increased when maternal grand sire effects were fitted into the sire model. The correlations between direct and maternal genetic effects were all negative, indicating antagonism between these effects, hence the need to consider both effects in selection programmes. Direct genetic correlations were higher than other correlations, except for maternal genetic correlations of FCR with TPG, LTG and AGES. There has been direct genetic improvement and almost constant maternal ability in production traits as shown by trends for estimated (EBVs) and maternal breeding values (MBVs), while phenotypic trends were similar to those for EBVs. These results suggest that maternal genetic effects should be included in selection programmes for these production traits. Therefore, the animal–maternal model may be the most appropriate model to use when estimating genetic parameters for production traits in this population.  相似文献   

Selected carbon fluxes in Pinus ponderosa-based silvopastoral systems, exotic plantations and natural pastures on volcanic soils in the Chilean Patagonia     

Francis Dube  Naresh V. Thevathasan  Neal B. Stolpe  Erick Zagal  Andrew M. Gordon  Miguel Espinosa  Katia Sáez 《Agroforestry Systems》2013,87(3):525-542

This study was undertaken to measure certain carbon (C) fluxes in a Pinus ponderosa-based silvopastoral systems (SPS) in Patagonia, Chile. Results are compared to those from adjacent 18-year-old managed pine plantations (PPP) and natural prairie (PST). Litter decomposition was determined using the litterbag method. Leached soil solution was collected with tension lysimeters at 80 cm depth, and soil respiration evaluated in situ with the soda lime technique. Wind direction influenced the litterfall distribution in SPS, with 94 % falling in the tree strips and within 3 m on the east side. In the first 6 months the initial needle decomposition was low and less than 5 % of the initial mass. The overall soil organic carbon (SOC) and N contents (0–40 cm depth) decreased significantly in the order SPS > PST > PPP, and within SPS were greater in the alleys, starting at 2.5 m from the tree strip, with the highest values always eastward of the strip, suggesting influence by the wind direction. Total soil respiration decreased in the order PST > SPS > PPP and leached C decreased in the order PPP > PST > SPS. In general, the mean annual soil moisture in the pasture alleys of SPS was twice that of PST. The air/soil temperatures decreased significantly in the second year only in PST and at 2 m and beyond from the tree strip in SPS. Soil moisture varied significantly among treatments, but showed the strong influence exerted by trees in the creation of a favorable microclimate within the pasture alleys of SPS.  相似文献   

Synthesis and bioactivity of some new N-aryl/alkyl/cyclohexyl-N'-(2,3-dihydro-2-oxo-4H-benz[e][1,3,2]oxazaphosphorin-2-yl) ureas     

Kiran YB  Gunasekar D  Devendranath Reddy C  Suresh Reddy C  Tran K  Le T  Berlin KD  Srinivasan S  Charitha Devi M 《Pest management science》2005,61(10):1016-1023

Several new substituted oxazaphosphorinyl urea derivatives of the type RR'P(O)NHC(O)NHR' were synthesized from alpha-(3-chloro-4-fluoroanilino)-o-cresol by reaction with chlorides of aryl/alkyl/cyclohexyl carbamidophosphoric acids in the presence of triethylamine at 0-50 degrees C. Their significant insecticidal and antimicrobial activity and promotion of Rhizobium bacteria growth in the soil without effect on the host tissue suggests their possible commercial application as ecofriendly pesticides and antimicrobial agents.  相似文献   

Heifers express G‐protein coupled receptor 153 in anterior pituitary gonadotrophs in stage‐dependent manner          下载免费PDF全文

Kiran Pandey  Onalenna Kereilwe  Hiroya Kadokawa 《Animal Science Journal》2018,89(1):60-71

We recently found that orphan G‐protein‐coupled receptor (GPR)153 is expressed in the anterior pituitary (AP) of heifers, leading us to speculate that GPR153 colocalizes with gonadotropin‐releasing hormone receptor (GnRHR) in the plasma membrane of gonadotrophs and is expressed at specific times of the reproductive cycle. To test this hypothesis, we examined the coexpression of GnRHR, GPR153, and either luteinizing hormone or follicle‐stimulating hormone in AP tissue and cultured AP cells by immunofluorescence microscopy. GPR153 was detected in the gonadotrophs, and was colocalized with GnRHR in the plasma membrane. GPR153 was also detected in the cytoplasm of cultured gonadotrophs. Real‐time PCR and western blot analyses found that expression was lower (P < 0.05) in AP tissues during early luteal phase as compared to pre‐ovulation or late luteal phases. The 5′‐flanking region of the GPR153 gene contained a consensus response element sequence for estrogen, but not for progesterone. These data suggest that some, but not all GPR153 colocalizes with GnRHR in the plasma membrane of gonadotrophs, and its expression changes stage‐dependently in the bovine AP.  相似文献   

The effect of conditioning and natural aeration methods on rate of moisture loss and crude protein content of Lablab purpureus herbage during hay-making     

Godfrey Manyawu  Irenie Chakoma  Siboniso Moyo  Sikhalazo Dube 《African Journal of Range and Forage Science》2016,33(4):247-251

The objective of this on-farm study was to develop an effective and labour-extensive method to cure forage Lablab purpureus ‘Highworth’ for resource-constrained smallholder farmers in the Goromonzi district, Zimbabwe in 2014. In a completely randomised factorial design, the drying rate of forage subjected to three conditioning treatments, viz. pressing with a plain water-filled 200 L steel drum, pressing with a water-filled 200 L steel drum covered with 14-gauge wire mesh, and chopping to 5?cm length with a machete, was compared with that of unconditioned forage. The conditioning treatments were subjected to three natural aeration methods, viz. Aframe, raised platform, and dry ground. Replicated four times, conditioned forage was cured at a swath density of 25?kg m?2 to cover 3?m2?per treatment over 28 d. Conditioning of forage had a significant (p < 0.05) effect on drying rate. However, conditioning did not have a significant (p > 0.05) effect on crude protein content. Aeration treatments did not have a significant effect (p > 0.05) on drying rate or crude protein content. Moisture loss rate was higher for forage conditioned with a wired drum and machete. Conditioning with a machete was most labour intensive compared with drum conditioning treatments. Laceration and pressing is an effective and labour-extensive conditioning method for resource-constrained smallholder farmers.  相似文献