H.T.A.M. Schepers

Precision Disease Control in Bed-Grown Crops

Matching spray volume to crop canopy sizes and shapes can reduce the use of plant protection products , thus reducing operational costs and environmental pollution. Developments on crop adapted spraying for fungal control are highlighted in arable crop spraying. A plant-specific variable volume precision sprayer, guided by foliage shape and volume (canopy density sprayer ; CDS ) was developed for bed-grown crops to apply fungicides . Sensor selection to quantify crop canopy and spray techniques to apply variable dose rates are evaluated based on laboratory measurements. Based on the laboratory experience a prototype CDS sprayer was built using either a Weed-IT ® or a GreenSeeker ® sensor to detect plant place (fluorescence) or size (reflectance). Variable rate application was either done with a pulse width modulation nozzle or a switchable four-nozzle body. Spray volume could be changed from 50 to 550 l ha−1 in 16 steps. Spray deposition , biological efficacy and agrochemical use reduction were evaluated in a flower bulb and a potato crop during field measurements using a prototype CDS sprayer. Spray volume savings of a prototype plant-specific sprayer are shown to be more than 75% in early late blight ( Phytophthora infestans ) control spraying in potatoes . In flower bulbs (lily ) it was shown that in Botrytis blight control on average spray volume could be reduced by 45%. In a potato crop biological efficacy was maintained at the same good level as of a conventional spraying. In a flower bulb crop biological efficacy of the CDS was lower than of conventional spraying, which means that spray strategy and dose algorithms need further research.

Agronomics and economics of late blight control in potato in West Java, Indonesia

Indonesia is the largest potato producer in Southeast Asia. Late blight (Phythophtora infestans) is one of the most important diseases especially in the rainy season. Therefore, farmers frequently spray fungicides to prevent infection. Forty farmers in West Java were trained in implementing good agricultural practices. To assess the impact of the training, late blight control strategies at the trainees’ fields were recorded. The baseline registration in the dry season of 2013 revealed that on average 16.6 times fungicides were applied. The average spray volume was 919 L ha-1, whereas the recommended spray volume ranges from 400 to 600 L ha-1 depending on the crop stage. Many farmers added an adjuvant to the spray mixture to increase the rainfastness of the fungicides. The fungicide costs ranged from 11.4 to 14.7% of the total production costs. The second registration, wet season of 2013/2014, showed a similar number of applications as in the dry season but the fungicide input was clearly higher due to a higher spray volume of 1,052 L ha-1 and more fungicides per application which caused higher fungicide costs ranging from 4 to 35% of the total production costs. Parallel and supportive to the trainings, three late blight demos were implemented in wet seasons. In the first demo (2013/2014), more recently registered fungicides controlled late blight similarly compared to the fungicide mixture often used by farmers, but they were 10-15% more expensive. In the second (2014/2015) and third demo (2015/2016), again the more recently registered fungicides did not perform better and were more expensive. A 20% reduction in spray volume had a similar effect on late blight control as the farmers’ practice using high volumes. At reduced spray volumes, the use of an adjuvant did increase late blight control. It is estimated that the spray volume can be reduced with 10-20% without loss of efficacy and thus save costs.

Netherlands public private partnerships aimed at Co-innovation in the potato value chain in emerging markets

Abstract Since 2013 the Netherlands Ministries of Economic and Foreign Affairs has been involved in private companies in research and development (R&D) in developing countries. This in a policy going “from aid to trade”. Especially in upcoming markets, R&D is carried out through Public Private Partnerships. Such partnerships not only include R&D organizations in the two countries but specifically also include businesses in both countries. This was to assure a logical flow of material and knowledge by all parties involved. Half of an R&D project is funded by the ministry and the rest is covered by a consortium of companies that contribute in kind and in cash. The policy is aimed at stimulating business development in developing countries and the Netherlands through cooperation and joint R&D. The paper explains how eleven consortia around potato business opportunities were formed, their R&D need was elicited and R&D projects formulated in the Asian countries China, India, Indonesia, Vietnam, Bangladesh and Myanmar, and Ethiopia and Kenya in Africa. In common are fact finding and descriptions of cropping systems, yield gap analysis and value chains in each country. Emphases differ with China looking for an integrated system of field operations, India for optimization of storage and processing, Indonesia to reduce pesticide and nutrient inputs, Vietnam for widening the varietal base, Bangladesh for combating late blight, Myanmar for cultural practices that lead to increased yield, Ethiopia where a potato processing unit is being established and Kenya importing seed potato from the Netherlands. Some content information is given as examples to illustrate the approach and some preliminary conclusion are discussed.