Fate of azadirachtin A and related azadirachtoids on tomatoes after greenhouse treatment

The degradation of the main azadirachtoids on tomatoes was studied after greenhouse treatment. These experiments were carried out at 1 and 5× the concentration recommended by the manufacturer. In all experiments the deposition of azadirachtin A (AZA-A) was below the maximum residue level (MRL). Even if at the highest dose, AZA-A half-life time calculated as pseudo first order kinetic was 1.2 days in agreement with the recommended preharvest interval (PHI) of 3 days. Experiments with a model system showed that sunlight photodegradation is the main factor influencing the rate of disappearance of AZA-A after greenhouse treatment while tomato epicuticular waxes doubled the photodegradation rate of AZA-A in a commercial formulation.     

INCREASING THE AGRICULTURAL USE OF SALINE WATER BY MEANS OF TRICKLE IRRIGATION1

ABSTRACT .A study was conducted in two arid zones to determine the effect of saline water applied to various crops growing in coarse-textured soil, using trickle irrigation. The test crops responded most favorably to this new method of water application in terms of plant development and yield. The method provides us with the possibility of raising the permissible salinity level of irrigation water, and thus to increase the water reserves suitable for agricultural use in the world.     

黑麦草、丛枝菌根对番茄Cd吸收、土壤Cd形态的影响

采用大田试验研究了在重金属Cd(5.943 mg·kg~(-1)污染下,黑麦草和丛枝菌根对2个品种番茄("德福mm-8"和"洛贝琪")生长、Cd含量以及对土壤微生物、酶活性、p H和Cd形态的影响.结果表明,黑麦草和丛枝菌根单一或复合处理显著提高了2个品种番茄果实、根、茎、叶和植株总干重,增幅分别为14.1%~38.4%和4.2%~18.3%、20.9%~31.5%和8.4%~10.3%、13.0%~16.8%和3.0%~9.5%、10.7%~16.8%和2.7%~7.6%、14.3%~36.6%和4.5%~16.8%.黑麦草和丛枝菌根单一或复合处理增加了土壤中细菌、真菌、放线菌数量及土壤脲酶、转化酶、磷酸酶、过氧化氢酶活性,且土壤微生物数量及土壤酶活性在不同品种和处理间的差异达到显著性水平(P0.05).与番茄套种黑麦草或接种丛枝菌根提高了土壤p H值,降低了土壤中可交换态(EXC-Cd)、碳酸盐态(CAB-Cd)和铁锰氧化态(Fe-Mn-Cd)和土壤中Cd总量,土壤中Cd总量降幅为16.9%~27.8%.2个番茄品种果实、叶、茎和根中的Cd含量分别显著下降了6.9%~40.9%、5.7%~40.1%、4.6%~34.7%和9.8%~42.4%.Cd主要积累在番茄的叶、根和茎中,果实积累较少.比较供试的2个番茄品种,果实Cd含量和积累量及植株Cd总积累量以"洛贝琪""德福mm-8".     

Tomato journeys from farm to fruit shop

Popular calls to buy products with fewer embodied greenhouse gas (GHG) emissions belie the complexity involved in providing accurate information necessary for such consumer decisions to be effective. This study follows greenhouse-grown tomatoes from Australian farms to fruit shops in Sydney, Australia and investigates practicalities of accounting for GHG emissions in this fresh food chain. Data came from semi-structured interviews with farmers, wholesalers who operate at the (wholesale) Sydney Markets and retailers. GHG emissions were estimated using quantitative methodologies including Australian National Greenhouse Account Factors. A qualitative analysis of stakeholder views and knowledge was also conducted. Conclusions include that, per unit of tomatoes, on-farm GHG emissions appear far greater than those from fuel used for transport to Sydney Markets, and from wholesale or retail activities. Food mile or more comprehensive carbon labelling would probably not be practical for this supply chain. Factors likely to affect potential change among higher emitting participants are costs and availability of lower GHG-emitting practices. Mixed-method studies help identify parts of a chain to target emission reduction efforts.     

Harvest time residues of pendimethalin in tomato,cauliflower, and radish under field conditions

Herbicides applied to vegetables play an important role in higher production of vegetables due to effective and timely control of weeds but at the same time herbicides residue may produce numerous environmental problems. The aim of this study was to determine whether application of herbicide for control of annual weeds in vegetable growing areas at recommended levels resulted in residues at the time of harvest. Thus, terminal residues of pendimethalin in vegetables such as tomato, cauliflower, and radishes were studies under field conditions. Pendimethalin was applied as pre-emergence herbicides at 1 kg a.i. ha^?1 to tomato, cauliflower, and radish crops. Soil and vegetables samples were collected from pendimethalin-treated plots at maturity to determine harvest time residues of pendimethalin. At harvest, 0.008, 0.001, and 0.014 μg/g residues of pendimethalin were found in tomato, cauliflower, and radishes, respectively.