The effect of solar radiation on dry matter accumulation in potatoes

April 03, 2023

There is, however, an effect of solar radiation on leaf morphology. When grown under high levels of insolation, the leaves are thicker (and so have a lower specific leaf area, SLA, value) as is evident from the measurement of the SLA expressed as cm² of leaf produced per g of leaf dry matter. This varies from 300 cm²/g in an environment with low radiation such as in winter in West Bengal with daily radiation of about 12 MJ/m² day compared to 200 cm²/g in the Andean highlands with around 24 MJ/m²/day.

Types of solar radiation

Solar radiation is divided into three types. The short waves are below 400 nanometer (nm) wavelength and contain ultra-violet radiation. The photosynthetically active radiation is between 400 and 700 nm, which also happens to be the visible light as we see it. The blue shortwaves and far-red long waves are invisible. Finally there are the long heat-producing waves above 700 nm. Of all solar radiation, only 50 percent is photosynthetically active. Of that, 30 percent is lost as it never reaches the chlorophyll in the chloroplast and a quarter of it is lost because short wavelengths are altered to longer waves producing heat. Converting the remaining solar energy into glucose only has a 30 percent efficiency. When finally sugars are formed, 35 percent of the sugars are lost in respiration and do not contribute to the structural mass of the potato plant.

Inefficient system

As these rounded figures show, capturing the sun through photosynthesis is not an efficient system. Even when a photon of light has exited chlorophyll to a higher energy state, it may fall back to the lower state, thus releasing a photon and radiation that can be measured: chlorophyll fluorescence. Fluorescence is more manifest when the plant is under sub-optimal conditions such as extremely high or low temperatures, drought, heat and lack of nitrogen. The strongest effects are seen when treated with herbicides as in the case with chemical haulm killing.

You may also be interested in:

Agritechnica focus on trends in potato technology

From 12-18 November Agritechnica takes place in Hannover, Germany. During the event there is a main focus on potatoes. Dr. Rolf Peters presents his vision on trends in potato technology. He states that potato growing has required a particularly high degree of flexibility from farmers in this year’s growing season due to the intensive change…

The efficiency of overhead irrigation for potato crops

Irrigation with sprinklers, rain guns, center pivots or linear systems – as opposed to furrow and drip irrigation delivering water under the canopy – distributes water overhead, much like natural rainfall does.

The advantages of drip irrigation in potato cultivation

Of all irrigation practices, furrow irrigation loses most water through drainage and also loses more nitrogen through leaching than other irrigation practices. Drainage through deep percolation on the other hand is an advantage as it avoids accumulation of salts at the surface. Besides, erosion is considerable as the water flow to some extent always transports…

Potato Association of America to showcase industry advances during annual meeting

The annual meeting of the Potato Association of America (PAA) is scheduled to take place from July 23rd to 27th, 2023. PAA members, potato researchers and industry partners will gather in Charlottetown, the capital of Prince Edward Island. ‘We look forward to welcoming the PAA family to Prince Edward Island for the first time since…