In addition to trips to the US for internships of practitioners, Pieniążek organized visits of Polish scientists dealing with horticulture on scholarships to primarily American agricultural universities, which allowed them to obtain doctoral degrees and professorship nominations.

[6] He was also the head of the British Council Władysław Filewicz scholarship created by Dr. Irena Modlibowska in England, which allowed several dozen scientists from Poland to complete internships at various research institutes in Great Britain.

During Stalinism in Poland, Pieniążek was an active exponent of the ideas of Ivan Michurin and Lysenkoism, which claimed that genes do not participate in inheritance.

[1] From the works of Michurin, Pieniążek appreciated the views concerning the cultivation of low-growing varieties of fruit trees commonly considered the most valuable.

[2] In the same period, he acted to defend fruit growers and vegetable gardeners against excessive taxation and collectivization and to keep their farms in private hands.

[5] The result of these activities was the continuous presence of fruit and vegetables on the Polish market, while there was often a shortage of other agricultural products in those years.

[9] In addition to his scientific activity, Pieniążek was involved in the widely understood popularization of gardening knowledge in Poland by publishing articles in the press on fruit trees and in the 1970s, taking part in weekly TV programs promoting the planting and cultivation of fruit trees and berry plants in home gardens.

[10][11] He was married to Janina Praska, born on August 28, 1914, in Warsaw, professor of plant physiology (marriage: September 1, 1939 in Ithaca).