Off-target movement of herbicides is a concern in California rice production, where sensitive crops are often grown nearby. Florpyrauxifen-benzyl and triclopyr are auxin mimics that are commonly used in rice systems. To steward florpyrauxifen-benzyl around the time of its initial registration in the state, research was conducted to compare the onset of foliar symptoms from simulated florpyrauxifen-benzyl and triclopyr drift onto grapevine, peach, and plum. The use rates on rice were 1/200×, 1/100×, 1/33×, and 1/10× of 29.4 g ai ha–1 florpyrauxifen-benzyl; and 1/200×, 1/100×, and 1/33× of 420.3 g ae ha–1 triclopyr. Herbicides were applied on one side of 1- to 2-year-old peach and plum trees and one side of established grapevines in 2020 and 2021. The general symptoms from applications of florpyrauxifen-benzyl and triclopyr were similar and included chlorosis, leaf curling, leaf distortion, leaf malformation, leaf crinkling, and necrosis. The symptoms from herbicides were observed on both sides of the grapevine canopy, whereas florpyrauxifen-benzyl symptoms on peach and plum were mostly observed on the treated side of the tree. Florpyrauxifen-benzyl and triclopyr symptoms were observed 3 d after treatment (DAT) for grapevines and 7 DAT for peach and plum. In all crops, most symptoms persisted through 42 DAT. Some grape clusters showed deformation and dropping of berries. All treated crops gradually recovered during the season regardless of application rates. Because symptoms in peach and plum were relatively minor, this research suggests that application precautions to reduce off-site drift are likely to minimize the occurrence of significant injury. However, grapevines were more sensitive and showed injury symptoms of up to 71% at 14 DAT with a simulated drift rate of 1/10× florpyrauxifen-benzyl. Therefore, extra precautions, such as using drift-management agents and closely monitoring wind speed conditions at the time of florpyrauxifen-benzyl applications may be necessary if vineyards are nearby.

We developed a partial equilibrium model to examine the welfare impacts of bird damage and its control in California wine grape production. The model incorporates the impacts of pest damage and its control and allows the impacts to vary regionally. Importantly, the model requires minimal information to apply; only elasticities, current market price and production data, and information on the cost and effectiveness of the pest control methods are needed. We rely on data from a recent survey of California growers and use the model to estimate changes in wine grape prices, production levels, and consumer and producer surplus that result from both bird damage and its control in three grape-growing regions of California. Results suggest that eliminating the threat of bird damage and control costs results in an increase in producer and consumer surplus of 1.3% and 3%, respectively. Furthermore, eliminating current bird control and allowing any resulting damage would decrease producer and consumer surplus by 6.6% and 11.5%, respectively. (JEL Classifications: Q11, Q18, Q57)

This paper reports a use of the real-options valuation methodology to analyze wine grape vineyard investment under price and yield uncertainty. Threshold annual rates of revenue per hectare to trigger entry and exit, respectively, were calculated for three different sizes of wine grape vineyards in northwest Victoria, Australia. The modeling identified lower exit and higher entry triggers than would be indicated by a conventional approach that ignores the uncertainty underpinning adaptive investment decisions. Between these triggers is a relatively wide gap of estimated indeterminacy in vineyard investment that highlights the intertwined influence of numerous economic factors—cost structure, economies of scale, market volatility, transaction costs, and sunk and salvaged asset valuation. Drawing on these determinants of vineyard investment and disinvestment, the paper discusses the role of investment incentives in affecting industry transformation and the scope for policy intervention to assist structural adjustment of the wine grape sector. (JEL Classification: C61, G11, I25, Q12)