Novel Nondestructive Technique to Determine Optimum Harvesting Stage of ‘Ataúlfo’ Mango Fruit

A portable spectrometer was validated to determine optimum harvesting stage of ‘Ataúlfo’ using dry matter and skin color as fruit indicators. To build the model, samples were collected as follows: a. Unripe; b. Green Mature 1; c. Green Mature 2; d. Green Mature 3; and e. Fully mature. Fruit were scanned with a near infrared spectrometer at three temperatures (15, 25, and 35 °C). Skin color (‘a’ value) was measured with a Minolta 400 colorimeter. DM was attained in a conventional oven by drying samples for 72 h at 60 °C. Model was built and validated three times. The best model linearity was obtained on skin color ‘a’ (R2 = 0.98), whereas for DM the R2 was only 0.70. For the first validation, the best predicted value was skin color ‘a’ with an R2 = 0.9144, followed by DM with an R2 = 0.7056. On the second validation, the adjusted predicted value for skin color ‘a’ had an R2 = 0.8798, while DM had an R2 = 0.4445. When comparing NIR versus Heat Units Accumulation, in Nayarit, ‘Ataúlfo’ skin color average difference between the spectrometer vs the colorimeter was only -0.04. For ‘Ataúlfo’ from Sinaloa, skin color average difference was only -0.06, but the correlation was higher (R2 = 0.90). In conclusion, measuring skin color with the NIR spectrometer has potential as a nondestructive technique to determine the optimum harvesting stage of ‘Ataúlfo’ mango.

Mechanised Threshing of Pod Grains used as food and Strategies to Optimise the Technique: A Review

Pod grains threshing using mechanical devices is essential in understanding the diversities involved in the application of machine–crop parameter combinations towards achieving best quality grain. The integration of pod grains’ physical properties in optimizing product quality which is vital to meet the increasing global requirement is limited. However, with computing and technological advancements into thresher design and evaluation have been found to be capable of meeting these needs which are of interest to researchers. Over the past three–four decades, the applications of the technology in reducing impact force through modification of peg geometry have attracted researchers’ widespread interest and the future looks promising. This review presents an overview of mechanical thresher development and the applications in the field of pod grain production chain. The role of grain physical properties in threshers design, operations and with force sensors to reveal the mysteries surrounding the causes of grain damage and how they can be minimised are stressed. The current trends and future advances of such studies are also presented.

Nondestructive Testing of Lettuce Nitrogen Stress Based on Multidimensional Image

Visible light near infrared (VS-NIR) hyperspectral combined with three-dimensional laser scanning was applied to extract the VS-NIR features of lettuce nitrogen between 400-1700 nm and 3D morphological features of the plants. Such combination realizes the rapid quantitative detection of lettuce nitrogen. This study is based on the hyperspectral image data cube achieved from lettuce leaves with different nitrogen levels. Stepwise regression sensitive area was used and adaptive band selection method was combined to extract the characteristic spectrum and feature image of lettuce nitrogen and characterize the average image intensity. Also; the error caused by moisture variation content in lettuce nitrogen image features was compensated. Then a model of lettuce nitrogen hyperspectral image diagnosis was built. The reverse engineering software Geomagic Qualify was used to repair and smooth interference noise and discontinuous range which are based on the 3D laser scanning data of lettuce. Accordingly, the stem diameter, plant height, leaf area, and biomass features of different nitrogen levels of lettuce are obtained and the model of nitrogen detection about lettuce growth features was built based on reverse engineering and integral method. Multi-scale fusion lettuce nitrogen detection model is built by using the acquired hyperspectral images with growing features of lettuce nitrogen and adopting genetic algorithm combined with partial least squares regression. Results show the correlation coefficient R of the built model is 0.95; the model precision is much better than single feature of hyperspectral images and 3D laser scanning model. The feature extraction algorithm and the eigenvectors provide the reference for development of facilities for online monitoring system of crop growth information.

Peanut (Arachis hypogaea L.) Response to Glyphosate plus Dicamba Combinations

Field studies were conducted in south and the High Plains of Texas as well as in southwestern Oklahoma during the 2014 and 2015 growing seasons to evaluate the effects of glyphosate plus dicamba combinations (1/16 X to 1 X of the 1.68 kg ae ha-1 rate) applied 30, 60, and 90 days after planting (DAP) on Spanish (Oklahoma) and runner (Texas) peanut. Rates were established to evaluate sub-labeled drift and direct application of a 1 X rate. Peanut stunting and death were more prevalent at the 30 and 60 DAP application while peanut were more tolerant of the 90 DAP application. In south Texas, peanut yields were reduced in both years when rates of ¼ X or greater were applied 30 and 90 DAP while rates of 1/8 X or greater reduced yield when applied 60 DAP. At the High Plains location, peanut yields were consistently reduced with rates of ½ X or greater applied 30 and 90 DAP and ¼ X or greater applied 60 DAP. In Oklahoma, peanut yield were consistently reduced with rates of ¼ X or greater applied 30 and 60 DAP and 1/16 X or greater when applied 90 DAP. Peanut grade was more affected by the 60 and 90 DAP application than the 30 DAP application.

Salt stress induced accumulation of biomolecules in groundnut genotypes

Salinity is one of the environmental limiting factors in agricultural production. The aim of this study was to find out one of more salt tolerant groundnut genotypes through monitoring the growth and changes in biomolecules under salt stress condition. Purposively four groundnut genotypes, including a Traditional variety, Zhingabadam, Binachinabadam-1 and Dacca-1 were grown under three salinity levels viz. 0, 3 and 5 dSm-1. The experiment was laid out in two factorial completely randomized design with three replications. This experiment was done in soil based pot culture up to 40 days. Increasing salt concentration drastically reduced all the growth parameters, and increase proline and sugar content of leaf. Among the varieties Traditional variety, Zhingabadam and Dacca-1 had statistically similar shoot and root dry weight. The leaves of the Traditional variety contain the highest amount of proline of 14.52 and 36.24 mg/100g fresh leaves in 3 and 5 dS/m salinity, respectively which was 236 and 737 % higher than that of respective control. At EC of 3 and 5 dS/m, the variety Binachinabadam-1 was appeared to be susceptible, having an increase of 6 and 113% proline content over the respective control. Based on the shoot dry weight, root dry weight, proline content, total sugar, reducing sugar and relative water content, the Traditional variety was strongly recommended to be grown in the coastal salt affected soils. The Zhingabadam and Dacca-1 variety also could be recommended as they had comparable performance of the Traditional variety.

Using Quinclorac to Control Annual Grasses and Palmer Amaranth in Grain Sorghum (Sorghum bicolor L.)

Field studies were conducted during the 2015 and 2016 growing seasons in south-central Texas to determine control of Palmer amaranth and annual grasses along with grain sorghum tolerance to quinclorac alone and in various combinations when applied to weeds < 5 cm (EPOST) or 10 to 16 cm tall (LPOST). When evaluated late-season quinclorac alone at 0.43 kg ae ha-1 controlled broadleaf signalgrass 72% when applied EPOST and 91% when applied LPOST. Combinations of quinclorac with either atrazine, pyrasulfotole + bromoxynil, dicamba, or dimethenamid-P controlled Palmer amaranth 88 to 100% when applied EPOST or LPOST; however, broadleaf signalgrass control with these combination was better when applied LPOST (75 to 95%) compared with EPOST (37 to 72%) applications. Texas millet control with quinclorac was poor in both years and was never greater than 54%. Quinclorac plus either atrazine, pyrasulfotole + bromoxynil, dicamba, or atrazine + dimethenamid-P caused at least 20% sorghum injury at one of three locations. No yield reductions from the untreated check were noted in either year; however, in 2016 all treatments with the exception of quinclorac alone at 0.29 kg ha-1 applied EPOST, quinclorac + pyrasulfotole + bromoxynil applied LPOST, quinclorac + atrazine + pyrasulfotole + bromoxynil applied LPOST, and quinclorac + dicamba at either application timing produced yields that were greater than the untreated check.

Design of multilayer microfluidic paper chip and its visual detection of pesticide residues

With the increase of China's grain production, the use of pesticides is gradually increasing. Traditional pesticide detection takes a long time and requires expensive experimental instruments, which is not conducive to the rapid and accurate detection of pesticide residues in the field. To solve this problem, this paper proposes a visual detection method of pesticide residues based on multi-layer microfluidic paper chips. The internal channel structure of paper chip is designed from the perspective of efficient mixing. Through the simulation of the mixed effect of three kinds of staggered channel structures, which are arc type, triangle type, and ladder type, the "ladder-type h-0.3, s-2.6" is selected as the best-staggered structure, and the mixing strength is 0.91534. The best simulation structure was tested by a colored reagent, and the image processing of 15 test results was carried out with MATLAB. The average mixing strength was 0.84, and the and the standard deviation was 0.022. The visual detection experiment of acetamiprid and profenofos in cabbage samples was carried out by using the device，The detection range of acetamiprid was 4~72 μg/kg, and the detection range of profenofos was 3~54 μg/kg . The recovery of acetamiprid was 75%~85%, and the recovery of profenofos was 80%~90%. The detection range and recovery rate indicate that the device has high repeatability and accuracy in the actual sample detection

Design and Simulation of the Operating Speed Regulation Algorithm of Plot Cabbage Seed Combine Harvester

Aiming at the problems of the single control scheme, the few aspects of monitoring and diagnosis, and the large delay time of the plot combine harvester, this paper designs the forward speed control algorithm of the plot Chinese cabbage seed harvester. This paper studies the theory of association rules, has used SQL Server to build a database including the job parameters of the main monitoring objects, and has mined the association rules between the job parameters and the feed amount through Analysis Service. Combining the knowledge of association rules and ordinary fuzzy PID algorithm, the article has built a model and performed simulation verification. The results show that the algorithm can adjust the forward speed reasonably and quickly when the feed volume increases.

Insects Associated with Cucumbers (Cucumis SativusL.) At Bamunka-Ndop(North West Region, Cameroon)

Studies on insects associated with cucumbers (Cucumis sativus) in Bamunka-ndop (North-West, Cameroon) under field conditions were conducted in 2017 and 2018 from April to July. The insect species diversity, the relative abundance, the frequency of visits and guilds were recorded on the plant from 7 am to 6 pm in a 2 hours time slots. Insects were found on the stem, leaves and flowers of Cucumber. There were 10 insect species belonging to 4 Orders. Out of these, four species belonged to Hymenoptera (54.15%), whereas the Coleoptera (33.18%), the Orthoptera (7.83%) and the Diptera (4.84%) owned two species each. Formica sp. being the most represented insect (24.42%) followed by A. mellifera (21.66%). Nectarivorous, pollinivorous, stems and leaves feeders and flowers and leaves feeders were found on the crop. The peak of activities of all the insect species was situated between 10 am and 12pm even though the temperature and the relative humidity of the study site appear not to affect their activities on the plant. These studies therefore indicated that the insects associated to cucumber should be exploited to work on their activities on cucumber and enhancing yield and quality of the fruits.

Efficacy of the Biopesticide NECO in the control of Ralstonia solancearum, causal agent of tomato bacterial wilt in Côte d’Ivoire

The tomato crop is confronted to numerous soilborne pathogens, including Ralstonia solanacearum, which considerably limits its production. In order to control this bacterium, a biological control approach has been considered by evaluating the efficacy of the NECO biopesticide against this bacteriosis. In vitro confrontations were carried out using a range of five concentrations of the biopesticide. In vivo, NECO solutions of 5 and 10 mL/L were incorporated into soil previously infested with R. solanacearum before transplanting tomato plants. Zones of bacterial growth inhibition were observed after the application of the NECO biopesticide. Results showed that the 20 mL/L concentration resulted in a higher inhibition rate. The biopesticide at the 10 mL/L concentration significantly reduced the incidence of bacterial wilt (54.05%) under in vivo conditions. The NECO biopesticide could be used as a control agent for Ralstonia solanacearum.