Influence of Water Content on the Quality of Pigeonpea Seeds

The species Cajanus cajan L. where pigeonpea is from presents a harvest potential in tropical regions for it is used as human and animal feed, besides being used as green fertilizer. However, the harvest area of this Fabaceae is still insignificant, due to especially the lack of quality seeds. In this context, it is possible to affirm that drying and store are portrayed as important steps for obtaining superior quality seeds. The aim of this study is to evaluate the physiologic quality of dwarf pigeonpea seeds, with different water content during storage. A factorial scheme 3 × 6 was adopted in the delimitation completely randomized, with four replications. Treatments were constituted by the combination of lots of seeds containing three different water contents (11%, 14% and 16%), submitted to a 10-month storage period, with evaluations every two months (0, 2, 4, 6, 8 and 10). Seeds were stocked in a bag type kraft under normal lab conditions, that is, no control. Physiologic quality of the seeds was evaluated through the following tests: Germination Pattern Test—GPT, first count of germination, accelerated aging and electric conductivity. It can be concluded that pigeonpea with hard seeds containing water content at 11% existing superior physiologic quality throughout the 10-month storage, under no controlled condition, certainly promoted by the less intense breathing from the reserves cumulated in the seed lot. Pigeonpea seeds storage with water content superior to 14% promotes a sharp decrease of physiologic quality, due to an increase in metabolic activity.

Physiological Quality of Soybean Seeds Treated with Carboxymethyl Cellulose and Fungicide

Soybean is the most produced oil crop in the world, with great increase in its annual production as well as great generation of waste from its industrialization. The soybean hulls can be used for the elaboration of products such as carboxymethyl cellulose (CMC), adding high value to this residue and it can be used as a coating polymer in seeds. The objective of this work was to analyze the physiological quality of soybean seeds treated with CMC and fungicide, recording images to verify the effectiveness of the coating in the seeds. The experiment was randomized into factorial scheme 2 × 4 with four replicates, two soybean cultivars M-7110 and M-7739 and four types of coating: without (control), CMC, fungicide and fungicide/CMC. The variables analyzed were: vigor (first count), germination test, accelerated aging, length and dry mass of the radicle and hypocotyl length. The images were made with a scanning electron microscope (SEM) with zoom of 50 and 200 times. The CMC used alone or with fungicide, provided good physiological quality of soybean seeds. In some analyzes there was difference between the cultivars M 7110 and M 7739. The combination of CMC and fungicide provided a better coating on the seeds.

Physiological Quality of Pigeonpea Seed after Application of Desiccant Herbicides

The pre-harvest application of herbicides may impair seed quality. This way, this paper was conducted to evaluate the effects of the application of desiccant herbicides on the physiological quality of pigeonpea seeds. Six batches of seeds from plants desiccated with glyphosate were evaluated at doses: 1.125 (B1), 1.5 (B2) and 1.875 L&middotha-1 (B3);and Gramocil (20% Paraquat + 10% Diurom) at doses: 1.5 (B4) and 2 L&middotha-1 (B5), and a control which received no application (B6). Seed viability was assessed through the germination standard test, and vigor through the first germination count, accelerated aging, electrical conductivity, seedling length, seedling dry matter and biomass density tests. The experimental design was the completely randomized, with four replications. Data were submitted to variance analysis, and when significant effects were observed, the Scott- Knott test was carried out at 5% probability using the SISVAR 5.1 software. The results showed that: a) the application of 1.875 L&middotha-1 of glyphosate was harmful to pigeonpea seed viability and vigor, evaluated through the accelerated aging test;b) applications of glyphosate in a 1.875 L&middotha-1 dose and Gramocil in 2 L&middotha-1 resulted in low vigor according to the electrical conductivity test of seeds;and c) the seed vigor measured by the first count, seedling length, seedling dry matter and biomass density test was not influenced by the type of desiccant applied.