Tips for the greenkeeper in summer

Today in Tiloom we want to give you the best tips for the greenkeeper in summer.

The summer season is characterised by a considerable increase in daytime and nighttime temperatures, which results in high rates of evapotranspiration. On the other hand, in C3 varieties, from 23 °C onwards, the number of length and mass of roots begins to diminish and even daily maximum temperatures above 35°C and nightly maximum temperatures above 25°C can lead to their death (Huang, B et al.).

It is therefore very relevant that we can find ourselves during the summer season in the most unfavourable situation for our field, that is to say, with higher water input requirements to the plant and less available volume in the soil as a consequence of lower root depth..

This shortage of water available to the plant itself requires water management. efficient irrigation and therefore monitoring of temperature, humidity and root depth will be vital.

The most efficient irrigation management is that which provides the turf with its net needs, leaving pore space also for oxygen and respiration, a physiological process that is even more important in these summer seasons. Therefore, as root depth decreases, irrigations should be increasingly shallower and more frequent, the opposite situation to that which occurs when salt flushing is required, deep and spaced irrigations, but this is not the situation we are discussing in this article and it is understood that there are no salinity problems.

Taking into account that root decline (to a greater or lesser extent is a generalised fact in summer) we will present different strategies to alleviate these phenomena as much as possible:

• Use of surfactants or surfactantsThese lower the surface tension of the water allowing better "wetting" of the soil and eliminating dry patches.

There are different types of surfactants or surfactants: anionic, non-anionic, polymers, sugar derivatives or humic acids.

The combination of wetting agents and micropinches will increase the hydraulic conductivityallowing the water to penetrate deeply.

• Use of growth regulators such as Trinexapac-Ethyl. Studies on C3 varieties have shown increased resistance to drought after application, due to the fact that the deceleration in growth and the physiological processes they promote reduce the plant's water consumption demand. Similarly, studies at the University of Arkansas have shown similar behaviour for hybrid Bermuda tramlines with similar treatments (see below).Source: Brouwer.N. 2014. University of Arkansas).
• Improving the irrigation uniformity. This is improved by calibrating the irrigation system, taking into account sprinkler location, rainfall, static and dynamic pressures, pumping, etc. Irrigation uniformities of around 50 - 75% are common. The higher the uniformity, the lower the water deficit problems. Nowadays POGO offers the best tool on the market for your study.

• Syringes o refreshment wateringThe application of water to the leaf tissue to reduce the temperature at specific times. It should not be an irrigation action per se, which should be carried out at night to replace water lost through evapotranspiration..
• Use of greens fans and air extractorsSubair vacuum blowers, the so-called "Subair vacuum blowers", to remove excess moisture.
• Use of mycorrhizae. Mycorrhizae are one of the most abundant types of symbiosis in the biosphere: they are fungi that interact with the plant and improve the absorption of water and nutrients from the root, allowing the attenuation of water stress in summer. Source: Ruiz-Lozano et al., 1995.

Mycorrhizae can be supplied either through biological inoculation or through organic amendments.

• Increased cutting height. Fast greens surfaces are to be achieved through thinning operations and not so much through low heights. There is a positive correlation between cutting height and root length.

• Nitrogen, Phosphorus and Potassium dosage adjustment. Root growth is based on nitrogen, it grows when photosynthesis takes place, if the leaf is at optimum chlorophyll content and the grass produces more carbohydrates than it consumes. Potassium is the nutrient that regulates the opening and closing of the leaf stomata and thus the evapotranspiration process by which the turf regulates its temperature. It is a key element in resistance to water stress. Sufficient phosphorus content. Phosphorus is part of the ATP molecule, the plant's energy unit. It is necessary for all physiological processes in the grass.
  

  We recommend keeping phosphorus and potassium levels slightly above MSLN levels.

• Nematode control which, as plant-parasitic worms, cause considerable root damage when temperatures are optimal for their growth between 21 and 27 °C, so they usually attack in spring and symptoms are seen in summer. They are often found in sports grounds because of the nematodes' preference for sandy soils.

• Insect controlThe insecticides used must be introduced through the felt mattress or "root mat". The insecticides used must be introduced through the felt mattress or 'fleece'.thatch"until it reaches the root zone. Incorporation with the aid of irrigation is recommended.

The following are some of the most common insects that cause root damage