Efficacy of Cover Crops for Pollinator Habitat Provision and Weed Suppression

Impacts of almond pollination service and inter-row cover cropping on honey bee colony strength and performance

Intensive agriculture has become necessary to meet the growing global demand for food and in some crops, successful fruit and seed production involves the activity of insect pollinators. Among insects, honey bees are one of the most efficient pollinators and in the agriculture industry, worth over 200 billion dollars annually, economic yield of some commodity crops, such as almonds, are heavily reliant upon pollination by honey bees. Almonds are a quintessential example of the commercial application of plant-pollinator dependency. Acreages of almonds mostly comprise of self-incompatible varieties that need bees for transferring pollen from the flowers of 'pollenizer' varieties to those of nut-yielding varieties, facilitating cross-pollination. Early season flowering phenology of almonds, when there are very few other plants in bloom, facilitates honey bee colony growth after the overwintering quiescence. Here, (i) we assessed colony strength and performance before and after almond pollination service and (ii) the impacts of availability of flowering interrow mustard-mix cover crops. Results show that there were consistently more frames of bees, pollen stores, brood, and adult bees in colonies returning from almond pollination service. The availability of mustard-mix cover crops supports increased colony strength through the season, facilitating long lasting positive impacts on honey bee health. Our findings suggest that agroecosystem management practices such as interrow cover cropping, strengthen the immediate and long-term positive impacts from pollination services by improving honey bee colony performance while simultaneously promoting ecosystem function.

Impacts of Wildflower Interventions on Beneficial Insects in Fruit Crops: A Review

Integrated pest management (IPM) has been practiced by the fruit industry for at least 30 years. Naturally occurring beneficial insects have been encouraged to thrive alongside introduced predatory insects. However, Conservation Biological Control (CBC) and augmented biocontrol through the release of large numbers of natural enemies is normally only widely adopted when a pest has become resistant to available conventional pesticides and control has begun to break down. In addition, the incorporation of wild pollinator management, essential to fruit production, has, in the past, not been a priority but is now increasingly recognized through integrated pest and pollinator management (IPPM). This review focuses on the impacts on pest regulation and pollination services in fruit crops through the delivery of natural enemies and pollinating insects by provisioning areas of fruiting crops with floral resources. Most of the studies in this review highlighted beneficial or benign impacts of floral resource prevision to fruit crops. However, placement in the landscape and spill-over of beneficial arthropods into the crop can be influential and limiting. This review also highlights the need for longer-term ecological studies to understand the impacts of changing arthropod communities over time and the opportunity to tailor wildflower mixes to specific crops for increased pest control and pollination benefits, ultimately impacting fruit growers bottom-line with less reliance on pesticides.