Instant estimation of rice yield using ground-based RGB images and its potential applicability to UAV

Rice (Oryza sativa L.) is one of the most important cereals, which provides 20% of the world’s food energy. However, its productivity is poorly assessed especially in the global South. Here, we provide a first study to perform a deep learning-based approach for instantaneously estimating rice yield using RGB images. During ripening stage and at harvest, over 22,000 digital images were captured vertically downwards over the rice canopy from a distance of 0.8 to 0.9m at 4,820 harvesting plots having the yield of 0.1 to 16.1 t ha-1 across six countries in Africa and Japan. A convolutional neural network (CNN) applied to these data at harvest predicted 68% variation in yield with a relative root mean square error (rRMSE) of 0.22. Even when the resolution of images was reduced (from 0.2 to 3.2cm pixel-1 of ground sampling distance), the model could predict 57% variation in yield, implying that this approach can be scaled by use of unmanned aerial vehicles. Our work offers low-cost, hands-on, and rapid approach for high throughput phenotyping, and can lead to impact assessment of productivity-enhancing interventions, detection of fields where these are needed to sustainably increase crop production

Superoxide dismutase and ascorbate peroxidase are constitutively more thermotolerant than other antioxidant enzymes in Chenopodium album

Thermal stability of antioxidant defense enzymes was investigated in leaf and inflorescence of heat adaptive weed Chenopodium album. Leaf samples were taken at early and late seedling stage in December (LD, 20 °C/4 °C) and March (LM, 31 °C/14 °C). Young inflorescence (INF) was sampled at flowering in April (40 °C/21 °C). LD, LM and INF crude protein extracts were subjected to elevated temperatures (5 to 100 °C) for 30′. Superoxide dismutase (SOD) was the most heat stable enzyme followed by Ascorbate peroxidase (APX). Two heat stable SOD isozymes were visible on native-PAGE at 100 °C in both leaf and INF. Some heat stable APX isozymes were more abundant in INF than leaf. Thermostability of catalase (CAT) increased with age and increasing ambient temperatures in leaves. CAT activity was observed up to 60 °C in leaves and INF while peroxidase (POX) retained activity up to 100 °C in INF due to one thermostable isozyme. Glutathione reductase (GR), dehydroascorbate reductase (DHAR, EC 1.8.5.1) and monodehydroascorbate reductase (MDHAR) showed activity up to 70 °C in both leaves and INF. DHAR activity was stable up to 60 °C while GR and MDHAR declined sharply after 40 °C. Constitutive heat stable isozymes of SOD and APX in leaves and INF may contribute towards heat tolerance in C. album