Green Manure Species and Sowing Time Effects on the Agronomic Performance of Common Bean

Abstract

An evaluation of sowing date effects on the development of green manure species and the subsequent effects on the agronomic performance of common bean (Phaseolus vulgaris L.) was conducted using three consecutive years of field trials. A randomized block design was used with a factorial treatment structure of 3 yr, three sowing dates and five green manure species {sunn hemp [Crotalaria juncea L.], slender leaf rattlebox [C. ochroleuca G. Don], velvet bean[Mucuna pruriens L.], pigeon pea [Cajanus cajan (L.) Millsp.], and jack bean [Canavalia ensiformis (L.) DC.]}, aiming to determine the agronomical performance of common bean in response to species and sowing date of different green manures. The dependent variables used to evaluate green manure development were "green manure shoot dry mass (GMSDM), green manure N accumulation (GMNA) and green manure nitrogen accumulation efficiency (GMNAE)". For common bean "common bean leaf area index (CBLAI), common bean shoot dry mass (CBSDM), number of pods per plant (NPP), number of grains per pod (NGP), total of grains per plant (TGP), 100-grain weight (100GW), grain yield (GY), grain harvest index (GHI), and nitrogen use efficiency (NUE)" were used to evaluate common bean performance. The GMSDM and GMNA both decreased when the green manure were sown in February rather than November, with the exception of velvet bean. Although the GMNA varied with year, species, and planting date, values above 90 kg ha -1 were common after November and December sowing and were sufficient to ensure good GY levels of subsequent common bean. Pigeon pea stood out because of its positive effect on the CBLAI, CBSDM, and NUE values of subsequent common bean. The GMNAE, NPP, NGP, NUE, and GHI were significantly correlated with GY. The best combination of these variables resulted in a common bean GY of 2000 kg ha -1 , which is 57% higher than the Brazilian average. These results indicate that the use of green manure can contribute to the sustainability of organic production systems in tropical regions.

Differences in Nodulation and Grain Yield on Common Bean Cultivars with Different Growth Cycles

“…The percentage of active nodules (AN) and the nodule dry weight (NDW) were determined as described by Ferreira et al (2010). The plant shoot was separated from the roots to determine the leaf area (LA), the shoot dry mass (SDW) (Ferreira, Stone, and Didonet 2013) and the Total-N by the Kjeldahl method (Liao 1981).…”

“…The experimental plots were kept in the field until the grain ripened stage (R9), when the plant canopy (PC), the number of pods (NP), the number of grains (NG), the 100 grains weight (100 GW) and the GY were determined as described by Ferreira, Stone, and Didonet (2013). The data from the two experiments were subjected to variance analysis and when statistical differences were found for the "F" test, the means were compared by the Skott-Knott test at 5% of probability using the SISVAR software (Ferreira 2011).…”

Polyphasic characterization of bacteria obtained from upland rice cultivated in Cerrado soil

“…At sowing time, seeds were inoculated with peat-based inoculant containing 1 × 10 8 cell g −1 of each isolate and reference strain. Rice plants were harvested at 40 days after emergence (DAE) to determine leaf area (LA), root volume (RV), root dry weight (RDW), shoot dry weight (SDW) according to Ferreira 20 , 21 and, the total N (N-Total) using the Kjedahl method, as described by Silva and Queiroz. 22…”

Depth of Sulfur Fertilization as Affecting Nodulation and Grain Yield of Common Bean

“…The roots were washed over a sieve to remove the excess of soil. The number of nodules (NN), nodule dry weight (NDW), root dry mass (RDM), leaf area (LA) and shoot dry mass (SDM) were determined as described by Ferreira et al (2010Ferreira et al ( , 2013.…”