The objective of this study was to evaluate the influence of Neem oil on insect management, on production and quality of palm fruits. The experiment was carried out at the Palma Agricultural Center, Federal University of Pelotas. Nine genotypes of palms (Butia odorata) were selected, presenting an estimated age of 20 years and production of four bunches. The doses of Neem oil used were: T1 (0.0 mL L-1), T2 (2.0 mL L-1), T3 (4.0 mL L-1) and T4 (6.0 mL L-1). At the beginning of maturation, three samples of 30 fruits each were collected and taken to the pomology laboratory. The experimental design was completely randomized and unifatorial. The means were submitted to analysis of variance and, when significant, were submitted to the Tukey test. The values of mean production cycle, SS/TA ratio, the epidermis colorimetry and number of lesions per bunch reduced in the treatments with Neem oil. The values of mean fruit mass per bunch, mean fruit mass, mean pulp mass, mean juice volume, pulp yield, number of fruits per bunch and effective fruiting increased in T4. The use of Neem oil is effective in the management of flower insects and palm fruits.
Aims: The aim of this study was to analyse the use of remote sensing as an alternative in monitoring water quality, and to analyse models that estimate the concentrations of chlorophyll-a (Chl-a) in a reservoir in the semi-arid region.
Place and Duration of Study: Field campaigns were carried out at the Pereira de Miranda reservoir, Pentecoste, in the State of Ceará (CE), at five sampling points, from December 2014 to December 2015.
Methodology: Limnological and spectral data were used, which were collected using a spectroradiometer. The limnological attributes of Chl-a and suspended sediments were analysed in the laboratory, and used to evaluate the spectral responses. Four three-band models were analysed for estimating the concentrations of Chl-a.
Results: The models of Lopes  and Gitelson et al.  gave the best performance, with respective satisfactory results for R2 of 0.75 and 0.79, MAE errors of 6.74 (μg.L-1) and 6.51 (μg.L-1), an NSE of 0.74 for both models, and RMSE of 9.01 (μg.L-1) and 8.93 (μg.L-1). From these results, the models were selected and applied in the campaigns of April and September 2015.
Conclusion: The use of remote sensing is therefore viable in estimating concentrations of Chl-a, collaborating to the development of research and in water resource management at lower cost.
Greenhouse experiment was conducted with two cultivars of common beans and four concentrations of potassium (1, 2, 10 and 20 millimolar –mM ) were supplied to the soil pots aiming to access variations in plant antioxidant defense systems (secondary metabolites and enzymatic mechanisms), growth parameters and leaf gas-exchange measurements. The total fresh leaf mass increased in both cultivars from 1 to 10 mM of potassium and the dry matter content decreased from 1 to 20 mM. Root volume significantly increased in Uirapuru cultivar. Potassium increased chlorophyll A in both in the range of 1 to 10 Mm. Catalase activity and carotenoids increased only in Dama cultivar. Potassium increased the photosynthetic activity in cultivar-dependent manner. Cultivar ‘Dama’ showed higher intrinsic water use efficiency, NDVI index, chlorophyll contents, total leaf mass and higher catalase activity. If the selection of cultivar under those traits is aimed, ‘Dama’ cultivar is a candidate and presented a linear stomatal conductance model.
Aim: To study the seasonal incidence pattern of gram pod borer, Helicoverpa armigera (Hübner) and tur pod fly, Melanagromyza obtusa (Malloch) in pigeonpea ecosystem.
Study Design: Complete Randomized Block Design.
Place and Duration of Study: Field experiments were conducted at Agriculture Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi during Kharif seasons of 2015-16 and 2016-17.
Methodology: The pigeonpea crop (cv. Bahar) was grown in plots of 10 m X 5 m (50 m2) replicated thrice and the crop fields were kept free from pesticide sprays. Five plants were selected randomly from each plot and weekly observations of the respective pests were taken through Plant Inspection Method (PIM) starting from 50 per cent flowering stage to till maturity of the crop and then correlated with the meteorological data.
Results: The results revealed that the infestation and severity of these insect pests were highly influenced by weather parameters. H. armigera population reached its peak (4.50 and 4.20 larvae per plant, respectively) in the 9th standard week of both the years. Similarly maximum incidence of M. obtusa in terms of maggot population was also recorded in 9th standard week with population of 8.00 and 7.75 maggots per plant. Correlation studies indicated that the population of these insect pests exhibited a significant positive correlation with maximum temperature whereas a significant negative correlation was established with relative humidity. The multiple regression analysis revealed that variations of different weather variables caused approximately 89.6 and 86.4 per cent variations in H. armigera population and 90.7 and 94.6 per cent variations in M. obtusa population during both years, respectively.
Conclusion: Different weather parameters determine seasonal activity and population dynamics of H. armigera and M. obtusa on pigeonpea and this information would help in developing weather based forecasting models for successful development and implementation of the pest management strategies against these major insect-pests of pigeonpea.
Fluoride (F) is one of the elements that are important in dental and skeletal formation in human beings. If present at optimal levels, it plays a very important role of preventing dental carries. However, its excessive uptake causes dental fluorosis and under extreme cases it causes skeletal fluorosis. F finds its route to human beings mainly through drinking water. However, substantial quantities of F can be taken by human beings through ingestion of food substances that contain elevated quantities of F. For example, tea can accumulate as high as 2965 mg kg-1 in their leaves. Therefore F in agricultural soils can be a source of F contamination. Despite the fact that F in crops can be a significant cause of fluorosis, studies on F dynamics in soils and its eventual uptake by crops has received little attention. Therefore this review article presents information on soil properties that enhance or deter F solubility in soils and its eventual bioavailability and the concomitant effects to crop plants. Soil physico-chemical conditions that affect the distribution of different F species and consequently its bioavailability and the uptake by plants have been discussed where pH is the most crucial factor. Cations like Ca and Mg in soils precipitate F thereby rendering it immobile. F in soils can be immobilized by organic amendments. Literature further shows that F is less mobile in heavy textured soils than in light textured soils. Therefore, this article reviews soil properties that can be manipulated so as to attain F immobilisation in soils and deter its uptake. The review has highlighted research gaps on F dynamics, mobilization/immobilization in soils. It is expected that this review will open a call for further research on the identified gaps